A Cyclic Approach to Large-Scale Short-Term Planning of Multipurpose Batch Plants

Abstract

In the process industries, final products arise from chemical and physical transformations of materials on processing units. In batch production mode, the total requirements for intermediate and final products are divided into individual batches. To produce a batch, at first the input materials are loaded into a processing unit. Then a transformation process, called a task, is performed, and finally the output products are unloaded from the processing unit. Typically, a plant is operated in batch production mode when a large number of different products are processed on multi-purpose equipment. That is why we consider multi-purpose processing units, which can operate different tasks. Symmetrically, a task may be executed on different processing units, in which case the duration of the task may depend on the processing unit used. For a practical example of a multi-purpose batch production plant we refer to the case study presented by Kallrath (2002).